The invention relates to injection devices and, more particularly, to an injection device for providing for the metered administration of an injectable product.
EP 0 298 067 B1 discloses an injection pen comprising a dual chamber ampoule (or ampule). The pen comprises a base section, a container accommodated by said base section, a drive unit and a metering device. A product dose is dispensed from the container through a needle by advancing in forward direction a piston arranged in said container. The drive unit comprises a driven member projecting into the container, displacing the piston in forward direction upon actuation of the drive unit. The length of the stroke, by which the driven member is displaced in forward direction of the piston in relation to the base section upon actuation of the drive mechanism, is set by means of the metering device. The base section is an enclosure surrounding the container, the drive unit and the metering device. The device, and others generally similar to it, is used for injection or infusion of a generally liquid drug solution.